A Global Randomized Trial Evaluating the FARAFLEX™ Mapping and Pulsed Field Ablation System With Electrographic Flow Mapping in Patients Undergoing Repeat Ablation for Atrial Fibrillation (ReDEFINE-AF)

The goal of the ReDEFINE-AF Clinical Study is to evaluate the safety and effectiveness of the FARAFLEX™ Mapping and Pulsed Field Ablation System with electrographic flow mapping in subjects undergoing repeat ablation for atrial fibrillation (AF).

Study Overview

• Status: Not yet recruiting
• Conditions: Paroxysmal Atrial Fibrillation (PAF); Atrial Fibrillation (AF); Persistent Atrial Fibrillation (PersAF)
• Intervention / Treatment: Device: FARAFLEX Mapping and Pulsed Field Ablation System

• Study Type: Interventional
• Enrollment (Estimated): 650
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Eliza Lawrence; Phone Number: (650) 215-1267; Email: Eliza.Lawrence@bsci.com
• Study Contact Backup: Name: Monika Bushko; Phone Number: (617)218-3963; Email: monika.bushko@bsci.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

1. At least 18 years old, or older if required by local law.

2. Subjects with symptomatic atrial fibrillation who have documented Persistent Atrial Fibrillation (PersAD) or Paroxysmal Atrial Fibrillation (PAF) with at least one documented symptomatic AF episode lasting at least 24 hours.

   AND Undergone one failed endocardial atrial fibrillation ablation procedure OR undergone no more than two prior endocardial atrial fibrillation ablation procedures that were both limited to PV and/or PW ablation.

3. Willing and capable of providing informed consent.
4. Willing and capable of participating in all follow-up assessments and testing associated with this clinical investigation at an approved clinical investigational center.
5. Willing to receive a LUX-Dx insertable cardiac monitor (ICM) during the study or already has a LUX-Dx ICM that was inserted within 6 months prior to consent, and willing to comply with the LUX-Dx Latitude Clarity transmission instructions.

Exclusion Criteria:

1. Any of the following atrial conditions:

   1. Left atrial anteroposterior (LA) diameter ≥ 6.5 cm, or if LA diameter is not available, non-indexed LA volume >100 mL.
   2. Current atrial myxoma.
   3. Current left atrial thrombus.
   4. Any PV abnormality, stenosis, or stenting. Common and middle PVs are admissible.

2. Any of the following cardiovascular conditions:

   1. History of sustained ventricular tachycardia or any ventricular fibrillation.
   2. Severe right ventricular dysfunction with documented echocardiography and/or hemodynamic data.
   3. Atrial Fibrillation (AF) that is secondary to electrolyte imbalance, thyroid disease, alcohol, or other reversible/non-cardiac causes.

   4. Presence of any of the following:

      • Current or anticipated pacemaker, implantable cardioverter defibrillator, or cardiac resynchronization therapy device.
      • Implantable loop recorder other than a LUX-Dx device
      • Interatrial baffle, atrial septal defect or patent foramen ovale closure device or patch
      • Left Atrial Appendage Closure or Occlusion Device

   5. Presence of any of the following:

      • Any cardiac valve prosthesis, ring, repair, or clip.
      • Mitral valve stenosis: moderate or greater.
      • Aortic stenosis: moderate or greater.
      • Severe mitral regurgitation.
      • Severe tricuspid regurgitation.
   6. Hypertrophic or amyloid cardiomyopathy.
   7. Any IVC filter, known inability to obtain vascular access, or other contraindication to femoral access.
   8. Awaiting cardiac transplantation or other planned cardiac surgery within the next 12 months.

3. Any of the following conditions documented during eligibility assessment or Baseline Assessment, as applicable:

   1. Heart failure associated with NYHA Class III or IV, as documented during eligibility assessment or Baseline Assessment.
   2. Most recent documented LVEF <40% within the previous 12 months.
   3. Body Mass Index (BMI) >45.0 kg/m², as documented during eligibility assessment or Baseline Assessment.
   4. Known coagulopathy or bleeding disorder.
   5. Contraindication to, or unwillingness to use, systemic anticoagulation or acceptable alternatives pre-, intra-, and post-procedure to achieve adequate anticoagulation.
   6. Women who are confirmed to be pregnant or lactating at the time of the ablation procedure.
   7. Severe lung disease, including but not limited to severe pulmonary hypertension, involving abnormal blood gases or requiring supplemental oxygen.
   8. Active malignancy other than squamous cell carcinoma.
   9. Clinically significant gastrointestinal problems involving the esophagus or stomach, including severe or erosive esophagitis, uncontrolled gastric reflux, gastroparesis, esophageal candidiasis, or active gastroduodenal ulceration.
   10. Known active systemic infection.
   11. Predicted life expectancy of less than one year per Investigator medical judgment.
   12. Subjects who are currently enrolled in another investigational study or registry that would directly interfere with the current study, except when the subject is participating in a mandatory governmental registry or a purely observational registry with no associated treatments.
   13. Required use of phosphodiesterase inhibitors within 24 hours of the ablation procedure.
   14. Known allergic drug reaction to nitroglycerin, excluding hypotension.
   15. Unwillingness to receive, or unable to tolerate, a subcutaneous, chronically inserted LUX-Dx ICM device.
   16. Presence of an active spinal cord stimulator.

4. Any of the following congenital conditions:

   1. Congenital heart disease with any clinically significant residual anatomic or conduction abnormality.
   2. History of known congenital methemoglobinemia.
   3. History of known G6PD deficiency.

5. Any of the following conditions in the medical history:

   1. Solid organ or hematologic transplant, or currently being evaluated for a transplant.
   2. Any prior history or current evidence of hemi-diaphragmatic paralysis or paresis.
   3. Any documented history of Prinzmetal angina or severe non-revascularizable coronary disease.
   4. Renal insufficiency if an estimated glomerular filtration rate (eGFR) is <30 mL/min/1.73 m², or any history of renal dialysis or renal transplant.
   5. Any other general health condition that, in the Investigator's medical opinion, would prevent participation in the study, interfere with assessment or therapy, significantly raise the risk of study participation, or modify outcome data or its interpretation.

6. Any of the following events within 90 days prior of the consent date:

   1. Myocardial infarction, unstable angina, or coronary intervention.
   2. Any cardiac surgery.
   3. Heart failure hospitalization.
   4. Pericarditis or symptomatic pericardial effusion.
   5. Gastrointestinal bleeding.
   6. Stroke, TIA, or intracranial bleeding.
   7. Any active non-neurologic thrombus and/or thromboembolic event.
   8. Carotid stenting or endarterectomy.
   9. Uncontrolled diabetes mellitus or a recorded HbA1c >8.0%.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Treatment Arm; Subjects will undergo EGF mapping using the OptiMap™ Catheter and System, followed by ablation of eligible EGF-identified extra-pulmonary vein sources using the FARAFLEX™ Mapping and PFA System.	Device: FARAFLEX Mapping and Pulsed Field Ablation System; Catheter used for electrophysiological mapping of cardiac structures and the treatment of paroxysmal or persistent atrial fibrillation.
Active Comparator: Control Arm; Subjects will undergo EGF mapping using the OptiMap™ Catheter and System; however, investigators and laboratory staff will remain blinded to EGF source maps until completion of the Index Procedure, and EGF-identified sources will not be ablated. For Control Arm subjects who have not previously undergone posterior wall ablation/isolation and who do not have documented durable posterior wall isolation, protocol-defined de novo posterior wall ablation will be performed using the FARAFLEX™ Mapping and PFA System.	Device: FARAFLEX Mapping and Pulsed Field Ablation System; Catheter used for electrophysiological mapping of cardiac structures and the treatment of paroxysmal or persistent atrial fibrillation.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
The Primary Effectiveness Endpoint (PEE) is the Proportion of Randomized Subjects in the Main Study Cohort achieving Treatment Success through the Day 365 Assessment.	The Primary Effectiveness Endpoint analysis will compare Treatment Success between the Treatment Arm and the Control Arm in randomized subjects in the Main Study Cohort.	Day 180 through Day 365 Assessment

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
The Secondary Safety Endpoint is the rate of protocol-defined device- or procedure-related Composite Serious Adverse Events (CSAE).	The secondary safety endpoint will be evaluated in Randomized Treatment Arm subjects and will not contribute to study success criteria.	Day 0 through Day 60

Collaborators and Investigators

• Sponsor: Boston Scientific Corporation

Study record dates

Study Major Dates

• Study Start (Estimated): November 1, 2026
• Primary Completion (Estimated): July 1, 2029
• Study Completion (Estimated): July 1, 2031

Study Registration Dates

• First Submitted: September 10, 2026
• First Submitted That Met QC Criteria: September 10, 2026
• First Posted (Actual): September 15, 2026

Study Record Updates

• Last Update Posted (Actual): September 15, 2026
• Last Update Submitted That Met QC Criteria: September 10, 2026
• Last Verified: September 1, 2026

More Information

Terms related to this study

• Keywords: Catheter Ablation; Pulmonary Vein Isolation; EGF; Pulsed Field Ablation; ICM; Electrographic Flow Mapping; OptiMap; Repeat Ablation; FARAFLEX; Posterior Wall Ablation
• Additional Relevant MeSH Terms: Cardiovascular Diseases; Pathologic Processes; Heart Diseases; Arrhythmias, Cardiac; Pathological Conditions, Signs and Symptoms; Atrial Fibrillation
• Other Study ID Numbers: PF340

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: Yes